Paraffin drive scraper

ABSTRACT

An elongated rod for lengthwise disposition and reciprocation in a well casing. The rod includes longitudinally spaced radially projecting abutments and an annular scraping member is loosely disposed on the rod for reciprocation thereon between the abutments. The annular scraping member includes a pair of halfannular sections pivotally joined together about aligned axes extending along a diameter of the scraping member and the halfsections are swingable between coplanar positions disposed generally in a plane normal to the centerline of the rod and folded positions with the free marginal portions of the halfsections swung toward each other.

United States Patent Levi J. Lack 1841 16th St., Abilene, Tex. 79603 805,691

Mar. 10, 1969 Mar. 16, 1971 [72] lnventor [21 Appl. No. [22] Filed [45 Patented [5 4] PARAFFIN DRIVE SCRAPER 5 Claims, 7 Drawing Figs.

[52] U.S.Cl 166/174, 166/176 [51] Int.Cl. ..E2lb37/02 [50] Field of Search 166/174- [56] References Cited UNITED STATES PATENTS 1,527,353 2/1925 Findley 166/176X 1,573,679 2/1926 Crosby 166/174 1,653,883 12/1927 Spencer..... 166/174 1,807,123 5/1931 McCarter 166/174 1,875,413 9/1932 Braly.... 166/174 2,124,869 7/1938 Rea 166/174 2,402,345 6/1946 Ratigan 166/176 3,273,648 9/1966 Barnard... 166/176X 3,330,358 7/1967 Ward 166/176X Primary Examiner-David H. Brown Attorneys-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT: An elongated rod for lengthwise disposition and reciprocation in a well casing. The rod includes longitudinally spaced radially projecting abutments and an annular scraping member is loosely disposed on the rod for reciprocation thereon between the abutments. The annular scraping member includes a pair of half-annular sections pivotally joined together about aligned axes extending along a diameter of the scraping member and the half-sections are swingable between coplanar positions disposed generally in a plane normal to the centerline of the rod and folded positions with the free marginal portions of the half-sections swung toward each other.

PARAFFIN DRIVE SCRAPER The scraper of the instant invention is designed primarily for use in oil wells and is to be mounted upon elongated rod sections reciprocated in the well casing. The scraper is constructed in a manner whereby it may be partially collapsed upon downward movement of the corresponding rod section and expanded upon upward movement of the corresponding rod section and expanded upon upward movement of the corresponding rod section. In this manner, quantities of paraffin adhering to the inner surfaces of the well casing may be scraped therefrom and elevated toward the upper end of the casing as the rod sections within the casing provided with scrapers of the instant invention are vertically reciprocated.

The main object of this invention is to provide a paraffin scraper which may be readily mounted upon a sucker rod or the like either at the bottom of a string of rods or in the middle of the string of rods and reciprocated with the rod string in order to remove paraffin deposits from within the associated well casing.

Another object of this invention is to provide a paraffin scraper constructed in a manner whereby it will automatically shift between contracted and expanded positions upon downward and upward movement, respectively, of the associated string of rods.

A still further object of this invention is to provide a paraffin scraper that may be readily attached to a rod string as the string is being lowered into a well casing.

Another important object of this invention is to provide a parafiin scraper including structural features thereof which will enable it to perform its desired function without undue wear and fatigue.

A final object of this invention to be specifically enumerated herein is to provide a paraffin scraper in accordance with the preceding object which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a fragmentary elevational view of a well casing with the portion thereof intermediate its opposite ends illustrated in vertical section and with a paraffin scraper constructed in accordance with the present invention mounted on a sucker rod section disposed in the well casing and in its operative position during upward movement of the sucker rod section;

FIG. 2 is a view similar to FIG. 1 but illustrating the position of the paraffin scraper during downward movement of the associated sucker rod;

FIG. 3 is an enlarged horizontal sectional view taken substantially upon the plane indicated by the section line 3-3 of FIG. 1;

FlG. 4 is a fragmentary vertical sectional view taken substantially upon the plane indicated by the section line 4-4 of FIG. 3;

FIG. 5 is a bottom plan view of the paraffin scraper; and

FIG. 6 is a perspective view of the paraffin scraper.

Referring now more specifically to the drawings, the numeral 10 generally designates a conventional well casing including a cylindrical inner surface 12 which is susceptible to having paraffin deposits build up thereon.

The numeral 14 generally designates a rod string consisting of a plurality of end aligned and joined rod sections 16. The lowermost rod section 16 is provided with an externally threaded lower terminal end portion 18 upon which an endpiece 20 is threadedly engaged. The endpiece 20 includes an upper end face 22 defining a radially outwardly projecting circumferentially extending abutment face and the upper end portion of the rod section 16 includes an inverted truncated cone-shaped enlargement 24. The upper end of the rod section 16 terminates upwardly in an externally threaded terminal end 26 which is threadedly engaged in the lower end portion 28 of the rod section disposed thereabove.

The scraper 29 includes an annular scraping member referred to in general by the reference numeral 30 consisting of a pair of half-annular sections 32. The annular scraping member 30 is loosely disposed on the rod section 16 intermediate the upper end face 22 and the enlargement 24 and the half-annular sections 32 are pivotally joined together by means of a pair of hinge assemblies referred to in general by the reference numerals 34.

Each hinge assembly 34 includes a pair of generally quarter annular hinge leaves 36 and 38 pivotally joined together by means of a hinge pin 40. The hinge leaves 36 include journal portions 42 while the hinge leaves 38 include journal portions 44. Each pair of corresponding journal portions 42 and 44 are aligned and receive the opposite ends of the corresponding pin 40 therethrough. The journal portions 42 and 44 project downwardly through the plane containing the undersurface portions of each pair of hinge leaves 36 and 38 and are received between the corresponding pair of opposing ends of the half-annular sections 32. in addition, each pair of hinge leaves 36 and 38 is secured to the corresponding half-annular section 32 by means of rivets 46. Accordingly, it may be seen that the hinge assemblies 34 not only serve to pivotally secure the half-annular sections 32 together but to also reinforce the half-annular sections 32.

With attention now invited more specifically to FIG. 4 of the drawings, it may be seen that the inner marginal portions of the half-annular sections 32 and the hinge leaves 36 and 38 are beveled as at 43 and 50 for clearance when the paraffin scraper is in the folded position thereof illustrated in FIG. 2 of the drawings immediately before the scraper abuts the enlargement 24 during the downward stroke of the rod section In operation, the paraffin scraper 29 may be readily secured to any given rod string 16 before it has been completely lowered into the well casing 10. Then, during reciprocation of the rod section 16 in a portion of the well casing 10 having a buildup of paraffin on the inner surfaces 12, the paraffin scraper 29 is seated on the abutment face 22 during upward movement of the rod section 16 in the manner illustrated in FIGS. 1 and 4 of the drawings. The paraffin scraper 29 has its outer marginal edge portions closely adjacent the inner surface 12 of the casing 10 and therefore operates to scrape paraffin from the inner surface 12 as the rod section 16 is raised. Then, when the rod section 16 is lowered, the paraffin scraper 29 will assume the position thereof illustrated in FIG. 2 of the drawings in a slightly collapsed position abutted against the enlargement 24. Of course, when the paraffin scraper 29 is being initially lowered into the well casing 10, it will also assume the position thereof illustrated in FIG. 2 of the drawings.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

lclaim:

1. In combination, an elongated rod for lengthwise disposition and reciprocation in a well casing, said rod including longitudinally spaced laterally outwardly projecting abutments, an annular scraping member loosely disposed on said rod for reciprocation thereon between the abutments, said scraping member including a pair of half-annular sections pivotally joined together about aligned axes extending generally along a diameter of the scraping member, said sections being swingable, relative to each other and said rod, between generally coplanar open positions disposed generally in a plane normal to the centerline of said rod and at least partially folded positions with the free edge portions of the half-sections swung toward each other, the inner peripheral edges of said half-annular sections being outwardly beveled toward the abutment toward which said edges face 2. The combination of claim 1 including a pair of hinge constructions each including a pair of hinge leaves pivotally secured together by means of a hinge pin, each pair of abutting ends of said half-annular sections having the leaves of one of said hinge constructions secured thereto wherein each of said hinge leaves is of a plan shape corresponding to the plan shape of the corresponding half-section end to which it is secured.

3. The combination of claim 2 wherein the confronting ends of said half-annular sections are spaced apart, said hinge leaves including journal portions projecting into the spaces between said confronting ends, and a hinge pin rotatably received through the journal portions of each pair of hinge leaves. t

4. The combination of claim 1 wherein the last-mentioned abutment is cone-shaped in configuration with its minor end portion closest to said scraping member.

5. The combination of claim 4 including a pair of hinge constructions each including a pair of hinge leaves pivotally secured together by means of a hinge pin, each pair of abutting ends of said half-annular sections having the leaves of one of said hinge constructions secured thereto, said hinge constructions being disposed on the sides of said half-annular sections adjacent the last-mentioned abutment. 

2. The combination of claim 1 including a pair of hinge constructions each including a pair of hinge leaves pivotally secured together by means of a hinge pin, each pair of abutting ends of said half-annular sections having the leaves of one of said hinge constructions secured thereto wherein each of said hinge leaves is of a plan shape corresponding to the plan shape of the corresponding half-section end to which it is secured.
 3. The combination of claim 2 wherein the confronting ends of said half-annular sections are spaced apart, said hinge leaves including journal portions projecting into the spaces between said confronting ends, and a hinge pin rotatably received through the journal portions of each pair of hinge leaves.
 4. The combination of claim 1 wherein the last-mentioned abutment is cone-shaped in configuration with its minor end portion closest to said scraping member.
 5. The combination of claim 4 including a pair of hinge constructions each including a pair of hinge leaves pivotally secured together by means of a hinge pin, each pair of abutting ends of said half-annular sections having the leaves of one of said hinge constructions secured thereto, said hinge constructions being disposed on the sides of said half-annular sections adjacent the last-mentioned abutment. 